Answer:

Explanation:
<u>Density
</u>
The density of a substance is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:

The cube has a mass of m=3.75 g and a volume of V=3 ml, thus the density is:


Since 1 kg=1000 mg and 1 lt = 1000 ml, the density has the same value but with different units:

DEFINITION:::::;;The type of reactions in which energy is releases to the environment are called Exothermic reactions.
EXAMPLE::: formation of carbon dioxide and urea formation are actually the examples of exothermic reaction..
Hope it helps
Answer:
Frictional force always acts parallel to two planes in contact with each other and in a direction opposite to that of relative motion of the two bodies. 2. Frictional forces are caused due to intermolecular interactions between the bodies. Frictional force is more for rough surface and less for smooth surfaces.
Explanation:
Polaris also called North star is the brightest star in the the constellation Ursa Minor. It remains stationary whereas entire north sky move around it. It the point of north celestial pole.
A) False. This is because All of the stars move in a counterclockwise path around Polaris.
B) False. Reason stated above.
C) True, As the stars move towards the Polaris there orbital radius decreases as they move smaller circles.
D) False, As the stars move towards the Polaris there orbital radius decreases as they move smaller circles.
E) True.
F) False.